1. Field of the Invention
The present invention relates to a thin and flexible light guide element having a cured coating. In particular, the present invention relates to a thin light guide element useful in a backlight module of a liquid crystal display (LCD).
2. Description of the Prior Art
Since a liquid crystal panel does not emit light itself, a backlight module, serving as a brightness source, is an important element of the display function of LCDs, and is very important for enhancing the brightness of LCDs.
In recent years, a new technique using a V-cut light guide plate has been developed in the field of backlight modules, which is popular for the panels used in notebook computers. The V-cut light guide plate is made mainly by directly micro-fabricating a prism on a light guide plate, and is used in the backlight module in combination with a prism sheet (reverse prism sheet) with downward serration, thereby replacing the two prism sheets with upward serration in conventional backlight modules. As shown in FIG. 1, the V-cut technique mainly employs one reverse prism sheet (3), one V-cut light guide plate (2) and one reflective film (1) under the reverse prism sheet, and a diffusion film (4) above the reverse prism sheet. Compared with the conventional backlight module, the brightness of the backlight module having a V-cut light guide plate can be enhanced by nearly 30%, and thus the required power can be reduced by one third, which is a considerable improvement on energy-saving performance.
However, the V-cut structure tends to make the light guide plate generate bright-and-dark stripes, and there is a need for a technical solution to remove the stripes. Moreover, due to the increasing quality demand of TFT-LCD factories, how to adjust the fine prism surface on one side of the light guide plate and the atomization surface on the other side of the light guide plate so as to optimize the overall performance is one of the focuses of development in recent optical element and precision processing technology.
Furthermore, with the development in soft electronic science and technology, displays have become light, thin, and flexible, and conventional CCFL has been gradually replaced by LED as the light source portion of the backlight module. In addition, conventional V-cut light guide plates normally utilize polymethyl methacrylate as the material, which is rigid and frangible, and are not suitable for flexible displays.
The present invention provides a thin and flexible light guide element suitable for LED light source to overcome the above disadvantages. In the present invention, the light guide element can be prepared by double-side coating the two sides of a flexible substrate with a roll-to-roll continuous process, and thus the thickness of the light guide element is greatly reduced. Since the light-emitting surface of the light guide element of the present invention is coated with a coating layer having a fine convex-concave structure, the hardness of the light guide element can be enhanced and the effect of light diffusion can be achieved after the coating layer is cured, and thus the objective of the present invention is realized.